Math Chpt. 4 Study Guide

Terms to Know:

Benchmark (Lesson 4-1)

A whole number or fraction that is easy to use when you estimate.
Example:You can use the benchmarks 0,1/2 or 1 to estimate sums and differences.
Add the 1/2,1 or 0 to the other to give the answer. - HoHo2009 HoHo2009 Feb 16, 2009corrections by - Pinkman2009 Pinkman2009 Feb 16, 2009

example, to add 1 12/90 + 5 45/50 you would round 12/90 down to 0 and 45/50 up to 1 so 1+5+1=7 - keithmeister09 keithmeister09 Feb 17, 2009

Elapsed Time (Lesson 4-7)

The time between two events.
Ex. 1:52PM-5:49AM=15hrs57min - professor2009 professor2009 Feb 17, 2009

How would you find the difference (elapsed time) from 8:12am -6:45pm? (Lesson 4-7)
  • Change 6:45 pm to military time (18:45)
  • Subtract 18:45 and 8:12.
  • That gives you 10 hrs. 33 min.
Make sure you use Military time to find the amount of time between A.M and P.M.- gotchalk5652 gotchalk5652 Feb 16, 2009
Also make sure that when you borrow a hour DO NOT ONLY ADD ONE MINUTE MAKE SURE YOU ADD 60 MINUTES!

Also make sure that when you are changing from A.M. to P.M. you add 12 hours to the later time. - kari4215 kari4215 Feb 16, 2009
Make sure you subtract (after you add 12 hrs) A.M. from P.M.- casers448 casers448 Feb 17, 2009




To Add and Subtract Fractions
You have to line them up the vertical way and then find a common denomator. Then add the numerators. From there you will add your whole numbers and then you have your answers. BUT ALWAYS REDUCE to SIMPLEST FORM if you can.
Corrections by - TmbrWlvsTchr TmbrWlvsTchr Feb 16, 2009

Make sure when you add and subtract fractions you find the same denominator.- polonia014 polonia014 Feb 16, 2009 Proofreading corrections by - TmbrWlvsTchr TmbrWlvsTchr Feb 16, 2009

Adding Fractions With Like Denominators (Lesson 4-2)
Take the numerators and add them. Keep the denominators the same. Example: 5/16+9/16=14/16 Make sure you reduce! 7/8 - momok9896 momok9896 Feb 16, 2009

To subtract a fraction like 2 and 1/3-2/3, you would have to borrow from the two and make it one the you add 3/3 to 1/3 and then you subtract and you get 1 and 2/3.

find a common denominator to add or subtract fractions. c(-:
(User:Monkeyboy2009)

Make sure you don't silly mistakes and leave a fraction improper - cheezer09 cheezer09 Feb 17, 2009~

Read the complete directions carefully before solving the problem. - Hurricane09 Hurricane09 Feb 16, 2009